The present invention relates to alarm systems for casting molds, and more particularly, to an alarm system with at least one sensing unit mounted to a casting mold for casting coins.
A conventional casting mold for metal casting is substantially composed of four parts, including a mold locking mechanism, a casting mechanism for melted alloy, a drawing mechanism for forming a cast, and a control system. For fabricating a cast by the casting mold, the first step is to quickly assemble the mold; then, the mold is slowly locked. Melted alloy is injected into the mold; after it is cooled and cured, a drawing process is performed. As shown in FIG. 5, during the drawing process to cast coins, a cast 3 formed from a mold cavity (not shown) of a graphite module 7 is clamped cooperatively by a press member 5 and a clamp base 6 of the drawing mechanism (not designated by a reference numeral), to be drawn leftwards out of the graphite module 7. Thereafter, the fabricated cast 3 is readily subject to subsequent processes.
However, during cast fabrication, problems such as inaccurate locking of the casting mold or improper temperature control, if being encountered, may undesirably cause deformation, displacement, burr edges or uneven thickness for the fabricated cast 3, or may lead to cracks of the graphite module 7. As the cast fabrication processes are automatically implemented, with the conventional casting mold not having a detecting mechanism for detecting failure of the cast 3, after completing the drawing process, the cast 3 would directly undergo subsequent processes even in the case of the cast 3 being defective with the above drawbacks or cracking of the graphite module 7. As a result, if failure of the cast 3 or cracking of the graphite module 7 cannot be immediately resolved, a casting oven (not shown) may thus be damaged and cause leakage, thereby leading to material wastes, increased costs for repairing the casting oven and time wastes for fabrication interruption.
A primary objective of the present invention is to provide an alarm system for a casting mold, which can detect a cast being improperly formed at an early stage of a drawing process; when failure of the cast is detected, an operator may immediately adjust or stop the drawing process to restore proper drawing conditions, thereby preventing further damage to the casting mold and reducing overall fabrication costs.
In accordance with the above and other objectives, the present invention proposes an alarm system for a casting mold, comprising: an alarm electrically connected to the casting mold; and at least one sensing unit electrically connected to the alarm, and spaced apart by a predetermined gap from a cast to be drawn from the casting mold. During a drawing process, if the cast is formed with failure in appearance such as deformation, burr edges or uneven thickness, the cast drawn out of the casting mold would come into contact with the sensing unit and thereby induce the alarm to generate an alarm signal to notify an operator who may immediately solve any operational problems.
Moreover, a drawing channel from which the cast is drawn out of the casting mold, may be internally formed with a graphite frame and a graphite plate; during the drawing process, if the graphite frame and/or the graphite plate are cracked by the defective cast with failure, a broken piece of graphite would be attached to and moved with the cast, to thereby touch the sensing unit and induce the alarm to generate the alarm signal.